1) Yes, she can "graduate" by fulfilling the high school graduation requirements for your state (such and such amount of math, science, etc.), or by taking the GED. Of the two options, the former will probably be more respected, esp if you have her take at least some CLEP / AP / community college courses.

2) A diploma is just a piece of paper saying you graduated. You can issue your own if you want, but it doesn't really figure into the equation - see above. Class ranking also won't be applicable, GPA you can calculate based on an aggregate of how well she does in her CLEP / AP / community college and how well you think she did in anything not covered by that. Colleges are pretty accepting of homeschoolers, they'll understand.

3) Community college courses are community college courses. If they're high school / college credit, that won't change just because you're also homeschooling._________________Homeschool Articles - Events - Support Groups